Rotating grass trimmers, lawn mowers, and edgers are commonly used for cutting grass and other foliage in places which are difficult or inconvenient to access using other types of lawn mower equipment. Such trimmers typically include a rotating head from which a cutting line is radially dispensed. Preferably, the line is flexible to increase the safety of the trimmer. As the head is rotated, the resulting centrifugal force causes the line to extend substantially straight out from the head. The line, being rotated at high speeds with particularly high velocity toward the end of the line distal from the head, serves as a cutting surface similar to a blade. In most applications, the last one-half inch of the line does substantially all of the cutting.
Typically, cutting line as described above is designed to be both safe and disposable. For this reason, it is often made from a flexible and inexpensive material such as nylon. However, polymers such as nylon are not good cutting materials and have a tendency to split at the cutting end. When the cutting end splits, the density of the cutting edge is reduced, thereby reducing the effectiveness of the line in cutting grass.
Furthermore, it is advantageous to increase the density of the flexible cutting line to improve the shear force of the line. Metal cutting lines have been used for this purpose but result in a cutting line which is less safe to use. Varying cutting line cross-sectional shapes have been implemented, but such designs add to the cost of manufacture.
U.S. Pat. No. 4,607,431 to Gay suggests that a filament loaded with abrasive particles may be used with the foliage trimmer disclosed therein. However, Gay in no way discloses or suggests a more specific composition or method of manufacture. Further, Gay does not suggest that a filament loaded with abrasive particles would have any beneficial characteristics over a non-loaded filament.
Thus, there is a need for a cutting line construction having increased density. Further, there is a need for such a cutting line which has a reduced tendency for end splitting. There exists a need for a cutting line as described above which retains the safety and inexpensiveness of conventional, flexible cutting line.